A cancerous tumor implies the appearance in the human body of a malignant neoplasm, which takes some of the nutrients for itself and worsens the general condition of the patient. It's no secret that cancerous tumors are a scourge. modern society. However, thanks to science, humanity has made significant progress in the study of this disease, and today there is a lot of information about malignant tumors.
Causes of the appearance of cancerous tumors
In the normal state, if an ordinary cell has some defects, it undergoes apoptosis, i.e., self-destruction. A cancer cell is different in that it cannot be destroyed and instead disguised as healthy. Therefore, the body perceives diseased cells as normal, and those, in turn, continue to divide, forming a cancerous tumor.
Why it happens? Unfortunately, despite the huge progress, the exact cause of the appearance of such neoplasms has not been established. However, most scientists are of the opinion about genetic disorders in the body.
However, according to studies at the end of 2015, due to genetic disorders, malignant cells occur only in 20-30% of cases. At the same time, it has been established that harmful factors have a much greater influence on the appearance of a tumor. To such negative impacts relate:
- Bad environmental situation.
- Inhalation of tobacco smoke.
- Acceptance of alcoholic beverages.
- Exposure to ionizing and ultraviolet radiation.
- Penetration of certain groups of viruses.
Despite this, the exact cause of the disease is still unknown.
Description of malignancy
What is cancer anyway? This is not a crustacean animal that lives in fresh water. A cancerous tumor is more unpleasant in appearance and carries a much greater danger.
The appearance of the tumor depends on the location and may vary in each case. Usually it is a soft knot that has a smooth or bumpy surface.
The dimensions are also unique. In the initial stages, the diameter is usually 1 cm. However, over time, the neoplasm has much big sizes. At the last stages of development, the diameter can reach 30cm.
After the collapse, the neoplasm changes its "familiar appearance". Now the tumor looks like a purulent mass with an unpleasant fetid odor.
Varieties and properties of tumors
Why is the exact cause so difficult to establish? The answer is simple - there are many varieties of malignant tumors, each of which is unique. To facilitate classification, neoplasms are usually subdivided depending on the type of affected cells.
At the moment distinguish the following types of tumors:
- Carcinoma - epithelial cells.
- Sarcoma - connective tissue, bones and muscles.
- Melanoma - if the tumor consists of melanocytes (cells responsible for skin color).
- Lymphoma is lymphatic tissue.
- Glioma - grows from glial cells in the brain.
- Teratoma - so-called. "germ" cells.
- Leukemia - brain stem cells.
Despite huge differences, all cancers have some of the characteristic features:
- Atypical cell structure.
- Rapid and uncontrolled growth, leading to the destruction or compression of healthy organs and tissues.
- Possibility of spreading to surrounding tissues.
- The tendency to form metastases (local pathological tumor foci) on neighboring or distant organs.
- The production of toxins that weaken the immune system, as well as leading to physical exhaustion and emaciation.
- Disguise as a healthy tissue (to deceive the body's defenses).
- High probability of mutation.
- The presence of mostly young cells.
- Accelerated filling of blood vessels.
Clinical picture
Symptoms of any tumor can be divided into 2 categories - general and specific. The first category includes signs that are characteristic of any type of cancer. As a rule, these are symptoms that occur due to the effects of toxins on the body and their destructive effects. An exacerbation of the clinical picture and deterioration of the condition usually occurs after the collapse of a cancerous neoplasm.
Common symptoms of a tumor include:
Clinical picture specific symptoms depend on the location of the tumor. For example, with brain damage, the patient begins frequent headaches, irritability, dizziness. If the tumor is localized in the respiratory tract, cough, shortness of breath, suffocation and hemoptysis (up to pulmonary bleeding) develop. If the bones are affected, there are painful sensations during movement, as well as frequent fractures due to the fragility of the bones.
Separately, it is worth mentioning metastases, i.e., the spread of tumor cells to healthy organs and tissues. Again, accurate clinical picture depends on each specific case, but nevertheless it is possible identify common symptoms:
- Significant enlargement of the lymph nodes.
- Enlargement of the liver.
- Minor bleeding (eg, hemoptysis).
- Change in hormonal status.
A cancerous tumor cannot be described in a nutshell. The main problem of this disease is the complexity of its study and understanding. Each neoplasm is unique and has its own characteristics. One can only hope that a cure for the "problem of the 21st century" will soon be invented.
8 out of 10 of all skin cancers are (also called cancerous basal cells). Basaliomas develop on areas exposed to the sun, especially on the head and neck.
Photo of basal cancer. Tumors may appear as raised areas (like this one) and may be pale, pink, or red. They may have one or more abnormal blood vessels. 
Basal cell carcinomas can occur anywhere in the body. They may appear as flat, pale or pink areas, like this one. Large basal cell carcinomas may have oozing or crusting areas. 
They may have a lower area in the center and blue, brown, or black areas. 
Basaliomas tend to grow slowly. Very rarely, this type of cancer spreads to other parts of the body. But if left untreated, the cancer can spread to nearby areas and infiltrate the bones or other tissues under the skin. 
Basalt cancer cells can also develop on the scalp, so it's important to check your scalp when you check the rest of your body for new signs or growths. Many doctors recommend doing this once a month. 
This type of skin cancer is more common in older people, but younger people can also be at risk. Probably because they now spend more time in the sun when their skin is exposed to the light. 
The photo shows basal skin cancer, which has a crust-like area. 
Photo of basalioma in the nasolabial fold 
In the photo: bleeding basalioma
For an ordinary person, the diagnosis of cancer sounds like a sentence. In fact, the disease is very different. Some of its types are easily detected and effectively treated. Others are rare and difficult to determine, but if they appear, they beat for sure.
Science classifies oncological diseases depending on which system or which organ they affect. In domestic medicine, cancer is only a carcinoma, that is, a malignant tumor of the epithelial cells of internal organs.
Actually, the very name of the disease appeared when the ancient sage Hippocrates, studying the causes of death of some of his compatriots, dissected the affected organ and decided that the tumor found there reminded him of cancer (in Greek - karkinos). Later, the ancient Roman physician Cornelius Celsus translated the term into Latin: cancer.
Other types of illness that do not affect the epithelium are called differently: sarcoma appears in the muscles, bones and connective tissue, lymphoma affects the lymph, and so on.
Blood cancer, brain cancer - these are common, but inaccurate, philistine terms.
Types of malignant tumors, if classified according to the affected organs and tissues, are several dozen. But only 12 types of cancer account for almost 70% of all cancers in Russia.
Fortunately, the most common does not mean the most deadly. Let's talk about the first and second, focusing on three parameters:
What are the risks of dying from a particular disease in a given period of time, such as a year. This indicator is called lethality.
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- Registered: 692,297 people
- Died in a year: 22,098 people
- Lethality: 3.0%
Seals in the chest are common, caused by many factors, including tumors. In most cases, neoplasms appear in the lobules of the mammary glands (cells responsible for the formation of milk) and the ducts connecting the lobules to the nipples.
The cells of the mammary glands, like all others, use receptors so that the incoming chemical signals cause the desired cellular reactions. How the receptors behave helps determine the type of breast cancer and find the most effective treatment.
Estrogen-dependent tumors
Normal breast cells and some cancer cells contain receptors that can capture and attract estrogen and progesterone into the cell. Receiving hormonal nourishment, the tumor grows.
Those types of cancer that are formed by such cells respond well to hormone therapy. Certain drugs block the receptors that accept estrogen and progesterone, hormones stop entering the cells, and the tumor stops growing.
Most breast cancers are like this.
HER2 positive tumors
Other receptors that accept the HER2 protein (epidermal growth factor receptor) also stimulate cell development. HER2-positive cancer subtype is rarer, but also more aggressive than estrogen-dependent tumors. However, it can also be affected by certain drugs that block the HER2 protein.
In oncology, sensitivity is a good indicator. The more sensitive the neoplasm, the better the body will respond to treatment.
Triple negative subtype
If the tumor does not have any of the above receptors, it is called triple negative. This is the rarest type of neoplasm listed. These tumors spread rapidly and are difficult to treat. They are more common in women with a mutation in the BRCA1 gene, which suppresses the growth of cancer cells.
- Registered: 531,981 people
- Died in a year: 5,258 people
- Lethality: up to 3.7%
Melanoma is not the most common, but the most dangerous type of skin cancer. A malignant tumor in this case grows and metastasizes at a tremendous rate.
Other, non-melanoma types of cancer (basal cell and squamous cell) are much more common, but they are less dangerous, more treatable, and generally have a higher survival rate.
The best way recognize skin cancer in time - pay attention to new or changed color or shape of skin lesions.
Particular attention should be paid to moles that are unlike others or have changed their shape.
These signs should make you consult a doctor (dermatologist or oncologist):
- asymmetry (one half of the mole does not match the size of the other);
- uneven edges (rough, blurry, jagged);
- the color is not like others, interspersed with yellow, brown or black in a single mole;
- diameter over 6 mm;
- any changes in size, color, shape.
Superficial spreading melanoma
The most common form of melanoma (about 70% of cases). It looks like a flat or slightly convex area of skin with fuzzy uneven borders that has changed color. May appear in place of moles.
Lentiginous melanoma
It is similar to the previous view and is formed close to the surface of the skin, often from age spots. It occurs in the elderly and those who spend a lot of time in the sun.
Acrolentiginous melanoma
Appears as a black or brown spot under the nails, on the soles, palms.
nodular melanoma
Very aggressive form. By the time of detection, as a rule, cancer has already penetrated deep into nearby tissues. This process is called invasion.
- Registered: 238,212 people
- Died in a year: 12,565 people
- Lethality: 5%
Timely diagnosis of prostate cancer can save lives. But early detection raises a difficult question: what is more terrible - the disease or the side effects of treatment?
The fact is that many prostate tumors develop very slowly and may not cause serious problems for years, or even decades. But treatment sometimes leads to undesirable side effects including incontinence and impotence.
In order not to miss the development of this type of cancer, it is recommended that all men after 50 years of age consult a doctor and begin to examine the prostate annually. And if oncological diseases were found in the next of kin, it is advisable to start regular examinations from the age of 45.
Adenocarcinoma
More than 95% of all malignant tumors of the prostate gland are adenocarcinomas that form from the epithelium of the gland (the root "adeno" in Greek means "gland"). But within this category, neoplastic cells take on a variety of forms. The WHO classification describes the variants: swollen cells, colloidal, cricoid (the nuclei are displaced to the periphery, so that the cells look like rings with stones). And this is not all types.
Oncologists use the Gleason classification, which is based on differentiation (that is, the degree of maturation) of cells.
The less differentiated tumor cells, the harder form cancer. Such neoplasms are assigned the fifth gradation: they are dangerous and spread rapidly. Well differentiated cells receive the first gradation. They look almost healthy.
small cell carcinoma
A rare and aggressive form of prostate cancer that is difficult to detect. Unlike adenocarcinomas, it does not secrete a signal marker protein, prostate-specific antigen (PSA), which is usually found in a blood test. The tumor consists of small round cells, hence the name.
Squamous cell carcinoma
This type of prostate cancer has nothing to do with glandular tissue. Squamous cell carcinoma affects the squamous epithelial tissue of the prostate, and since PSA levels do not rise, it is difficult to detect. Carcinoma is very aggressive, the average life expectancy after its detection is slightly more than a year. Fortunately, it is rare: less than 1% of all cases of prostate cancer.
- Registered: 177,755 people
- Died in a year: 8,386 people
- Lethality: 5%
Almost all cancers begin in the epithelium of the nephron tubules - these are the main cells of the kidneys. Unfortunately, at an early stage, the disease practically does not manifest itself. A tumor can only be detected on an ultrasound of the kidney, if for some reason it is prescribed.
As the cancer progresses, so do the symptoms. They usually include blood in the urine (which may or may not be present), pain in the peritoneum, and a lump in the kidney area that can be felt.
Kidney cancer has long been considered chemo-resistant, but researchers are making more and more progress with drug treatments.
Until recently, any kidney cancer was classified as renal cell carcinoma. Now the disease is divided into subcategories.
Clear cell kidney cancer
The most common type, it accounts for up to 85% of cases. It is difficult to diagnose at an early stage.
papillary kidney cancer
This category, in turn, is divided into two subtypes. The first accounts for up to 5% of all cases of kidney cancer, the second - up to 10%. They differ in the size of the affected cells and the risk of metastasis formation: in the first case, these cells are small, in the second case they are large and more often lead to metastasis to other organs.
The first subtype often has a hereditary nature. Mitogen (a gene that causes a tumor) is transmitted from parents through germ cells - gametocytes.
- Registered: 167,585 people
- Died in a year: 1,117 people
- Lethality: 0.6%
Cancer thyroid gland responds well to treatment. Sometimes it is found after the appearance of a bump on the throat (this is how the enlarged thyroid gland makes itself felt), sometimes when the patient complains of difficulty swallowing, breathing, or a hoarseness of voice.
Only 5% of thyroid tumors develop aggressively and threaten other organs.
Many neoplasms grow so slowly that recently they have even ceased to be considered malignant.
Most thyroid tumors do not respond to chemotherapy, but some new developments are promising. For example, kinase inhibitors help to block an enzyme present in tumor cells. They also prevent the growth of new blood vessels.
Differentiated tumors
About 90% of thyroid cancers are well-differentiated tumors. They are divided into subgroups: papillary, follicular. They are more common in women and young adults and have a favorable prognosis.
Medullary cancer
Sometimes it is caused by the inheritance of a mutation in the RET proto-oncogene. Patients with this abnormality are often advised to remove the thyroid gland. Otherwise, the chances of successful treatment are significantly reduced.
Anaplastic cancer
The most aggressive type of thyroid carcinoma. Such neoplasms grow rapidly, respond poorly to treatment and actively metastasize to other organs.
- Registered: 128,264 people
- Died in a year: 4,946 people
- Lethality: 5.3%
Lymphoma is any malignant process that begins in the lymphatic system. The most commonly affected lymph nodes are small oval organs that cleanse the body of debris such as viruses, bacteria, and cancer cells. The nodes are connected by vessels through which not blood flows, but lymph. It is a fluid containing white blood cells - lymphocytes.
The lymphatic system takes fluid and waste products from the bloodstream. Lymphomas weaken immune system increases the risk of infections.
If you have swollen lymph nodes, contact your doctor as soon as possible. This is not necessarily a lymphoma: other diseases can also manifest themselves in this way.
The lymphatic and circulatory systems are interconnected and permeate the entire body. These are the pathways that cancer uses to spread metastases.
The lymphatic system is complex, so lymphomas are complex diseases. There are a great many of their categories and subcategories, which differ significantly from each other.
Hodgkin's lymphoma
Begins with lymphocytes. The most common form of classical Hodgkin's lymphoma, which is characterized by the appearance of giant lymphocytes. They are called Reed-Berezovsky-Sternberg cells. In 5% of cases, malignant cells are histiocytes that look like popcorn.
Most cancer cells are susceptible to DNA damage. That's what chemotherapy is for.
With the help of special substances, doctors destroy DNA strands. Affected cells cannot reproduce and die.
The first FDA (Food and Drug Administration) chemotherapy for Hodgkin's lymphoma was given in 1949. Nitroyprit was used - an analogue of the chemical warfare agent mustard gas.
Today, other drugs are used in chemotherapy. Moreover, they are used successfully: according to statistics, 9 out of every 10 people recover.
Non-Hodgkin's lymphomas
These forms are much more diverse. Many subgroups are more aggressive than the Hodgkin form. If the cells stick together, the lymphoma is called follicular (from the Latin folliculus - "pouch"). Cancer cells can spread within the lymphatic tissue evenly without clustering. In this case, the lymphoma is said to develop in a diffuse manner.
A promising new treatment for non-Hodgkin's lymphomas is based on the use of T-lymphocytes. These are immune cells that are present in the blood. Geneticists work on them in laboratories to place special chimeric antigen receptors (CARs) on their surface. These CAR-T lymphocytes can recognize proteins that help tumor cells hide from the patient's immune system. This is the fundamental principle of immunotherapy in general: to identify cancer so that the immune system can attack it.
- Registered: 113,182 people
- Died in a year: 6,094 people
- Lethality: 4.5%
Blood in the urine is a characteristic and often the first symptom of cancer. Bladder. This occurs in 8 out of 10 cases of the disease, more often affecting men.
Bladder cancer often spreads to other parts of the urinary system, including the kidneys, ureters, and urethra.
And this happens even after a course of treatment.
About 95% of bladder cancer develops in the cells lining the organ from the inside. These cells - the urothelium - are constantly in contact with urine and, more importantly, with the substances that it removes from the body, and these are carcinogens. For example, chemical compounds contained in tobacco smoke or exhaust gases can thus provoke the development of a malignant neoplasm.
This type of cancer quickly adapts to medications. Therefore, it is important to choose new types of treatment. For example, one of them - gene therapy - uses modified viruses that act specifically on bladder tumors. As a result, cancer cells are marked with a hormone that gives the immune system a sign: here is the danger, this cell must be attacked and destroyed.
- Registered: 86,129 people
- Died in a year: 7,208 people
- Lethality: 6%
Most types of leukemia - as blood cancers are properly called - begin in hematopoietic stem cells. These cells are responsible for hematopoiesis and are found in the bone marrow.
At an early stage, leukemia can hint about itself with signs related to the characteristics of the blood:
- The appearance of purple and red spots on the skin. Most often, these point hemorrhages (petechiae) are formed on the chest, back, arms. The spots are small, often mistaken for a rash and ignored.
- Unusual bleeding. For example, the most small scratch may bleed for a long time.
If these symptoms are accompanied by other signs - a decrease in immunity, unexplained weight loss, swollen lymph nodes, fatigue, weakness, a visit to the therapist is required.
Leukemias are divided into acute and chronic. Acute ones spread rapidly, chronic ones do not. Many types of chronic leukemia are well controlled and patients can live with them for years or decades.
The number of cancers that can be called chronic is only growing. There are more people living with cancer today than at any time in history.
Chronic lymphocytic leukemia (CLL)
It affects lymphocytes - white blood cells that are responsible for fighting infections. This is one of the most common blood cancers.
Recurrent CLL is difficult to get rid of: tumors become insensitive to previous treatment, especially chemotherapy.
A new type of drug should slow the spread of the disease. It aims to identify specific mutations that increase resistance to chemotherapy.
Acute lymphoblastic leukemia (ALL)
Children are more likely to suffer from this disease. Standard treatment includes chemotherapy, and five-year survival in juveniles is significantly higher than in adults (85% versus 50%).
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- Registered: 19,837 people
- Died in a year: 18,020 people
- Lethality: 39.9%
There is no mistake in the numbers: the death rate from pancreatic cancer is indeed almost equal to the number of cases registered. But this speaks not so much about the aggressiveness of the disease (although it should not be written off), but about a significant underestimation of primary patients. That is, cancer is so asymptomatic that it is diagnosed either at the final stage, when it is no longer possible to help a person, or even posthumously.
Chronic pancreatitis, adenoma or pancreatic cyst can simplify early diagnosis. These diseases can be harbingers of cancer.
Pancreatic cancer develops slowly. It takes about 10 years for the first degenerate cancer cell to start growing aggressively. But even after that, it takes another 5-7 years for a detectable tumor to form.
As soon as the first metastasis appears, the process accelerates: from this moment until the death of the patient, an average of 2.7 years passes. The chances of recovery or suspension of the development of the disease, unfortunately, are small.
Adenocarcinoma
Doctors have five forms of pancreatic cancer. Adenocarcinoma, which is formed from the epithelium of the ducts, is the most common of them. It occurs in 80-85% of cancer cases.
acinar cell carcinoma
In this case, neoplasms develop from cells that produce digestive enzymes - acini.
Squamous cell carcinoma and others
Squamous and undifferentiated cancer and cystadenocarcinoma are much less common. Like other forms of pancreatic cancer, they have an unfavorable prognosis.
- Registered: 8,590 people
- Died in a year: 9,859 people
- Lethality: 38.4%
In this case, the situation with the diagnosis is even bleaker. Liver cancer is often determined either posthumously or already at the final stage, when the patient is only a few months or even weeks away.
The reason for this is the same as in pancreatic cancer. Oncological diseases of the liver most often develop almost asymptomatically.
This means that the person is not worried about anything. And when pain appears in the right side and other signs appear, medicine is already powerless.
Depending on the origin, malignant neoplasms of the liver are divided into two types.
Primary liver cancer
This type includes primarily hepatocellular carcinoma, also known as hepatocellular carcinoma (HCC), or hepatocellular carcinoma (HCC). This is the name of a malignant tumor that develops directly in the liver cells - hepatocytes.
Less common are the other three types of disease:
- cholangiocarcinomas (cholangiocellular cancer) - tumors that develop from the epithelium of the intrahepatic bile ducts;
- mixed hepatocholangiocarcinomas - they affect the cells of both the liver and the intrahepatic bile ducts;
- fibrolamellar carcinoma.
These types of cancer are called primary because the oncoprocess begins in the liver itself, and does not come to it from other organs.
Metastatic liver cancer (secondary)
Such tumors penetrate the liver with metastases - from other diseased organs. Secondary cancer is much more common than primary cancer, since almost all organs can metastasize to the liver.
- Registered: 13,820 people
- Died in a year: 6,903 people
- Lethality: 29.9%
Like all of the most dangerous types of cancer, this one has no symptoms in its early stages. Malignant neoplasms, developing, narrow the lumen of the esophagus. It doesn't hurt and is almost imperceptible. So, some difficulties with swallowing - first dense and solid food, then semi-liquid, and later even water and saliva.
These difficulties increase gradually.
When a person realizes that something is wrong with him, and goes to the doctors, the cancer has already reached the 3-4th stage.
Unfortunately, almost incurable.
Depending on the place where the tumor appeared, cancer of the thoracic region (in its upper, middle and lower thirds), cervical and abdominal sections of the esophagus is isolated.
Adenocarcinoma of the esophagus
This tumor develops from the cells of the inner lining - the mucous layer of the esophagus and spreads deep into its wall. Adenocarcinoma usually forms in the lower part of the esophagus, near the stomach.
Squamous cell carcinoma of the esophagus
This type of malignant neoplasm appears in the flat cells lining the lumen of the esophagus. Squamous cell carcinoma most commonly occurs in the upper and middle parts of the esophagus.
Other malignant primary tumors of the esophagus
Less common, but still found: spindle cell carcinoma (poorly differentiated squamous cell carcinoma), verrucous cell carcinoma (highly differentiated squamous cell carcinoma), pseudosarcoma, mucoepidermoid carcinoma, glandular squamous cell carcinoma, cylindroma (cystic glandular carcinoma), primary oat cell carcinoma, choriocarcinoma, carcinoid and primary malignant melanoma.
Metastatic esophageal cancer
Occasionally, the oncoprocess in the esophagus is triggered from the outside - by metastases from other organs. Most often, these are metastases of melanoma and breast cancer. In addition, tumors of the head and neck, lung, stomach, liver, kidney, prostate, testicle, bone tissue metastasize into the esophagus.
Metastases usually spread in the connective tissue stroma surrounding the esophagus, while primary esophageal cancer grows from the mucosa or submucosa of the esophagus itself.
- Registered: 144,010 people
- Died in a year: 50,176 people
- Lethality: 21.9%
In Russia, this type of cancer is especially deadly. Every second patient who is diagnosed with the disease dies within a year - this is called a one-year mortality.
This is partly because the complex structure of the lungs makes it difficult to detect and treat a tumor in time. It grows, gives metastases to the bloodstream, lymphatic system and other organs.
More than 80% of neoplasms are found at this stage, when it is almost impossible to help the patient.
Small cell (oat cell) cancer
Small cell neoplasms often form in the bronchi (airways) and are very aggressive: metastases appear quickly. This type of cancer is more common in smokers.
Non-small cell cancer
More than 90% of lung cancers are non-small cell neoplasms, and about 40% of these are adenocarcinomas.
From 25 to 30% of non-small cell lung cancer is formed on the inner surface of the bronchi - these are squamous cell carcinomas. The rest of the tumors are grouped into the category of "large cell carcinoma".
- Registered: 139,591 people
- Died in a year: 28,512 people
- Lethality: 14.4%
Stomach cancer is one of the most common types of cancer in Russia (and in the world). A malignant tumor develops from the cells of the inner lining of the stomach.
Depending on the place where the neoplasm is located, there are:
- cancer of the upper (proximal - close to the esophagus) sections of the stomach;
- cancer of the middle sections - the body of the stomach;
- cancer of the lower (distal - closer to the duodenum) sections.
However, this classification is incomplete: the tumor can spread to two or more departments and capture the entire stomach.
Like other malignant neoplasms, stomach cancer can grow deep into the wall of the organ, as well as into other organs and tissues.
For example, spread along the digestive tube to the esophagus, duodenum, pancreas, liver... Tumor cells can be carried with the blood stream to distant organs, such as lungs and bones.
The main problem is that in the initial, curable stages, gastric cancer is often asymptomatic. Or it disguises itself as other diseases of the gastrointestinal tract - the same gastritis, pancreatitis, colitis or an ulcer. The tumor is discovered by accident: for example, when a patient is prescribed an endoscopic examination due to strange sensations in the abdomen.
But often stomach cancer is detected only when it has already manifested itself as distinct symptoms, has metastasized and has become incurable.
Adenocarcinoma
This type of cancer is formed in the glandular epithelium of the stomach. Adenocarcinoma can be:
- highly differentiated (a high cylindrical epithelium is formed);
- moderately differentiated (flatter, cube-like cells);
- poorly differentiated (video-modified cells almost do not rise above the surface of the epithelium).
In terms of cell shape, perhaps the most aggressive type of adenocarcinoma is signet ring cell carcinoma of the stomach.
Squamous cell carcinoma
The least common type of tumor. Occurs between the layers of the glandular epithelium of the stomach from flat cells.
Glandular squamous cell carcinoma
This tumor combines elements of adenocarcinoma and squamous cell carcinoma.
Neuroendocrine carcinoma
It is a rare but highly malignant form of stomach cancer. As a rule, it gives a lot of metastases.
undifferentiated cancer
This is a tumor whose cells are different sizes: can be both small and large (respectively, we are talking about small or large cell cancer), as well as polymorphic - in this case, all transitional cell forms are present.
- Registered: 383,510 people
- Died in a year: 40,543 people
- Lethality: up to 8.1%
The intestine has two sections: the small intestine and the large intestine. The main division of the latter is the so-called colon with a total length of up to 1.5 meters. It is her cancer that strikes most often.
The lethality of bowel cancer is relatively low. But because of its prevalence, it is second only to lung cancer in terms of the number of deaths.
Tumors that affect the intestines can grow for a long time, up to 15–20 years. Sometimes neoplasms develop from polyps - these are abnormal growths of tissues over mucous membranes. Every third or even every second has them, but few people notice them. Less than 10% of polyps degenerate into malignant tumors.
Cancer cells can invade the veins and arteries of the intestines, as well as the vessels of the lymphatic system (this process is called lymphovascular invasion). Blood and lymph wash the entire body, so the risk of infection of other organs increases.
Mucus-forming tumors
These tumors spread rapidly and differ in that they contain a lot of extracellular and intracellular mucus. The latter pushes the nucleus against the cell wall, which makes the cell look like a ring. Ring-shaped cancers are less treatable than others.
Important facts about cancer
Tumors are benign. This means that they are stable, surrounded by the tissue from which they are formed, and will not spread throughout the body. They are harmless.
Other tumors invade neighboring tissues. These are malignant neoplasms.
Cancer can be pre-invasive, that is, in the initial stages of development, when tumor cells do not germinate into the organ on which they are formed. At this stage, the treatment gives the best result. But over time, developing, the cancer penetrates the surrounding tissues and can metastasize to other organs.
Cancer cells can also penetrate into the veins and arteries, as well as into the vessels of the lymphatic system. Blood and lymph wash the entire body, so that the risk of infection of other organs increases.
The shape and type of tumor cells can determine which treatment will be most effective.
Tumor cells are tested for sensitivity to treatment. The higher it is, the better the prognosis. Most cancer cells respond to DNA destruction. It is the destruction of DNA strands that drugs for chemotherapy are engaged in.
Tumors often survive and grow faster because they grow through the blood vessels that feed them. This process is called angiogenesis.
After treatment, it is important to determine how many affected cells remain in the body. Modern research, such as PCR (polymerase chain reaction), detect even trace amounts of such cells.
Methods for the treatment of oncological diseases are actively developing. A cancer vaccine is being tested, which is made on the basis of the patient's cells. These cells are trained in laboratories to activate the immune system to fight cancer and then returned to the human body.
After surgery, adjuvant therapy is used - chemotherapy, which destroys small metastases and mutations that underlie tumors.
Some types of cancer are inherited. It is possible to identify genes that increase the risk of developing the disease, and to prevent or detect the disease at an early stage. This procedure is called genome sequencing.
All oncological diseases do not manifest themselves at first. Therefore, if you have any unusual symptoms, it is worth consulting with a therapist. And of course, regularly undergo scheduled preventive examinations.
Designers - Oleg Selivanov, Ekaterina Denisenko.
Editor - Alina Mashkovtseva.
Proofreader - Olga Sytnik.
Typesetter - Dmitry Naumov.
The body of each person consists of a huge number of cells. All of them perform specific functions. Normal cells grow, divide, and die in a pattern. This process is carefully controlled by the body, but due to the influence of many negative factors, it is disturbed. The result of this is uncontrolled cell division, which can later transform into an oncological neoplasm.
General information
A cancerous tumor consists of cells that divide uncontrollably and lose the ability to recognize "their own". They can penetrate into other tissues and organs of the body, preventing their normal functioning. Cancer cells are different healthy topics that, instead of dying in a timely manner, they continue to intensively divide. In addition, oncological neoplasms produce various toxins that constantly poison the patient's body.
Why "cancer"?
Malignant neoplasms are characterized by excessive reproduction. Mutated cells not only actively poison the body, but also begin to penetrate layers of other tissues. Therefore, the tumor constantly becomes larger, and also gets the opportunity to grow into other organs and tissues. Affected cells, stretching through healthy ones, form rays. They look almost the same as the claws of crustacean creatures. For this reason, such neoplasms got their name. A photo of a cancerous tumor is presented later in the article.
What contributes to the development of cancer?
Chemical carcinogens are one of the most common causes It is noteworthy that this applies to both local effects and effects on the whole organism as a whole. A striking confirmation of this is the development of lung cancer in people who abuse tobacco. Meanwhile, builders dealing with asbestos may face cancerous lesions of the pleura, chimney sweeps - with a tumor of the scrotum.
Apart from chemical carcinogens, physical ones are also a great danger. It's about radiation. They emit ionizing radiation and the harmful effects of ultraviolet radiation. They contribute to the development of skin carcinoma.
The formation of cancerous tumors also causes a genetic predisposition. Girls whose mothers had breast cancer are three times more likely to develop the disease than those who do not have a family history. Moreover, a similar pattern can be traced in the case of cancer of the endocrine gland and colon. Currently, scientists have been able to prove a genetic link with dozens of varieties of malignant tumors.
The geographic area in which a person is located can also be a cause of cancer. So, for example, in a population that lives in the same area, some types of tumors can appear much more often than others. This is due to a large combination of factors, which includes climate features, eating habits, environmental conditions and much, much more.
It is impossible not to note the harmful effects of oncogenic viruses. They are called so because they can provoke the formation of cancerous tumors. Hepatitis B has been found to be a frequent cause of liver cancer. There are cases when a tumor of the cervix arose due to the herpes virus of the second type.
Main manifestations
Cancer can be accompanied by a wide variety of signs and symptoms, so there is no general pattern. It all depends on where exactly the neoplasm is located, at what stage of development it is and whether it has reached a large size. However, there are general signs that may directly or indirectly indicate cancerous tumors. Symptoms most often are:
- Elevated temperature body and fever. These signs are manifested in almost all people with cancer. Those who are already undergoing treatment are especially susceptible to it. The latter can have a negative impact on the immune system, which makes the body much more susceptible to various infections and viruses.
- Unreasonable weight loss. This symptom is manifested in many people who are faced with oncology. The most susceptible to it are those whose cancerous tumor has affected the organs. gastrointestinal tract or lungs.
- Excessive fatigue. As the disease progresses, the person begins to feel more and more tired. This symptom may also appear on early stages tumor development, especially if it causes chronic blood loss. The latter often accompanies cancer of the stomach or colon.
- Pain. Sooner or later, a person will experience unpleasant and uncomfortable sensations on the most different stages development of pathology. Severe pain may indicate the presence of several tumors at once. They can be located, for example, in the testicles or bones.
How fast does cancer progress?
The development of cancer is a rather lengthy process. In most cases, a cancerous tumor does not grow quickly. However, with some of the most aggressive types of pathologies, things can be different. It depends on a large number of factors, including a person's age, general health, and more. On average, about three to five years pass from the onset of development to the appearance of the first symptoms. In some cases, this process can take up to a decade. At the same time, there are also such varieties of cancer that can kill a person in just a matter of months. It is in connection with this that it is not possible to name specific terms of the life expectancy of patients.
Initial stages of development
Currently, oncologists classify tumors depending on the stage in which the disease is located. Initially, the neoplasm receives a clear localization. At the first stage of development, cancer is located only in a limited area. At the same time, the tumor has not yet had time to grow into other organs and tissues, so the presence of metastases is excluded.
At the second stage of development, the formation increases in size. Nevertheless, it does not have time to get out of the organ in which it is localized. At this stage, metastases may already begin to appear. However, they are located only in nearby lymph nodes.
Final stages of development
Reaching the third stage, the tumor increases even more in size. At this stage, the process of its disintegration begins. Cancer penetrates the walls of the organ in which it is located. In nearby lymph nodes, many metastases are found.
When the tumor grows into neighboring organs and tissues, it is assigned the fourth stage. At the same time, all malignant tumors that can give distant metastases are included in the same category. At these stages of development, the disease is extremely difficult to treat.
Stages of cancerous tumors are exhibited for patients only once. They remain with them for the rest of their lives. The stages do not change even if the cancer does not return after treatment. However, they should not be confused with the clinical groups into which patients are divided (there are 4 in total).
What are metastases?
A cancerous tumor is dangerous because it can spread throughout the body. Metastases are new foci of its development. Through the lymphatic channels, the affected cells spread and affect other tissues and organs. Metastases can literally permeate the entire body. The liver, lungs, bones, and brain are most commonly affected. It is multiple metastasis that is one of the most common causes of death from oncology.
Cancer and its external manifestations
Many people who suspect they have cancer want to know what a cancerous tumor looks like. Currently, the Internet presents a huge number of images illustrating oncological diseases. However, it should be noted that not all of them correspond to the real signs of a particular tumor. That is why it is strongly recommended not to diagnose yourself on the Internet and, at the first suspicions, sign up for a consultation with an oncologist. It is not possible to independently determine a cancerous tumor from a photo from the Web. However, there are also signs that you can notice yourself:
- Enlarged lymph nodes.
- Seals under the skin.
- Sores or sores that appear for no reason and do not heal for a long time.
- Spots on the skin that begin to noticeably increase in size.
Tumor in the chest
Breast cancer is a fairly common occurrence. The incidence of this disease is increasing every year. This is partly due to the fact that modern medicine makes it possible to diagnose it at an early stage of development. However, according to statistics, it is breast cancer that is one of the most common causes of female death today. At the same time, the number of cases among patients of working age is increasing.
Health care in Russia and around the world is making progress in the fight against breast cancer in women. This is facilitated by both the increased detection of the disease and the fact that the disease is identified precisely at the initial stages of development. There was a decrease in mortality in the first 12 months after initial diagnosis. Timely detected tumors are treated much more successfully, while the life expectancy of patients increases. That is why regular preventive examinations and visits to the mammologist are shown to all women over 18 years of age.
Non-surgical treatment
In order to stop the development of cancerous tumors and reduce their size, various methods are used. The most commonly prescribed chemotherapy, immune and radiation therapy. They can be used individually or all together - depending on the specific case. Such techniques are systemic and cannot save the patient from the consequences of metastasis.
Chemotherapy is currently considered the main component of cancer treatment. In this case, the affected cells are affected by various drugs. Often, chemotherapy is prescribed to increase the effectiveness of the upcoming surgical intervention. It may include antitumor, antibacterial, hormonal and many other agents, including cytostatics and antimetabolites.
Surgical intervention
Removal of a cancerous tumor is a radical way to treat it. Affected cells can be excised along with the organ in which they are localized. Nearby lymph nodes are also often removed. However, radical therapy cannot help if the disease has already developed to the fourth stage.
Currently, for the treatment of oncology, symptomatic surgical intervention is often performed. This technique is aimed at eliminating the main manifestations of the disease, which pose a danger to the life of the patient. So, for example, symptomatic surgical intervention is performed when intestinal obstruction occurs. The problem is eliminated, but the tumor remains in place.
If the operation is not possible due to objective reasons, then palliative therapy is prescribed. This technique is aimed at prolonging the life of the patient and increasing its comfort. In this case, the tumors are usually removed, but the lymph nodes are not subjected to surgery. The impact on them can be carried out through radiation therapy and other techniques that help slow down the development of the tumor, but only for an indefinite time.
Finally
Still in the early XXI century, according to statistics, worldwide the number of patients with cancer was 10,000,000 people. Scientists predict that by 2020 this figure will grow to 16,000,000. This is due to the deteriorating state of environment and ecology in general, as well as the wide spread of bad habits in all segments of the population.
In order to reduce the likelihood of cancer, it is necessary to lead a healthy lifestyle (eat right, quit smoking and alcohol, provide moderate physical exercise and avoid harmful ultraviolet radiation) and always undergo routine diagnostics. The chances of early detection of malignant neoplasms increase every year. It is thanks to advanced prevention that the number of cancer patients in Europe has been reduced by 20%.
The human body consists of many elementary cellular particles that make up all organs and systems. The growth of the body and the restoration of tissues, as a rule, occurs due to cell division. These processes are triggered and controlled by special chemical signals. As a result of impaired proliferation of the constituent particles of organs, cancer cells.
Distinguishing features of cancer cells
During cell division, new elements exactly repeat the structure of the mother cell. At a young age, this process develops exponentially. In adults, the formation of new cells is determined by the need to replace aging or damaged tissues. Tissue renewal occurs at different rates and depends on the location of the organ. So, for example, the epithelium requires the most regular replacement. It should be taken into account that all cells exist for a given period of time, after which they are destroyed (apoptosis).
The cancer process can begin in any cell of the body, as a result of malignant transformation of physiologically healthy tissues. Pathological changes in cellular elements arise due to gene mutations that affect growth and life cycle fabrics. Types of cancer cells vary depending on the location of the pathology.
All types of oncology are characterized by:
- Uncontrolled.
- Tumor tissues do not perceive and do not respond to signals from physiologically healthy cells.
- Pathological elements tend to spread to other parts of the body.
- Mutated cells remain structurally immature.
Structure of cancer cells
The key element of all cells, including cancer cells, is the DNA molecule, which determines the composition, function and growth of the cell. This molecule contains all the genetic information (chromosomes). Humans have 22 pairs of autosomal chromosomes and 1 pair of sex chromosomes. Thus, the genetic material from parents to child is inherited in equal parts. In cells, the unit of heredity is the gene, which is a small piece of DNA. There are about 25,000 such elements.
Specialists associate the formation of a malignant neoplasm with a violation of the normal structure of the DNA molecule, which in oncology is defined by the term "gene mutation". At the same time, the human body has special defense mechanisms with the help of which the following happens:
- Replacement of a damaged DNA cell.
- Self-destruction of the altered cell.
But, unfortunately, in some cases there is an increase in the number of gene mutations. In the presence of 6 or more changes in the structure of the DNA cell, cancer cells.
Types of gene mutations
There are two main types of mutations:
- Spontaneous. Cancer cell division, in most cases, is considered the result of a spontaneous gene mutation that periodically occurs in all tissues of the body. The number of such anomalies increases under the influence of such risk factors as tobacco smoking, alcohol abuse, radiation and harmful working conditions.
- Hereditary. Sometimes mutated genes that increase a patient's sensitivity to the cancer process are passed from parent to child. Thus, germline mutations are formed when members of the same genetic chain have an increased risk of oncological morbidity.
Cancer cells - division:
Types of cancer genes
Geneticists have discovered three types of genes in the human body that control cell growth and division. Some people may inherit a mutated version of these genes, which is the cause.
- Oncogenes are genes that can get out of control of the body and turn into a cancer cell. Oncogenes are formed from proto-oncogenes that control the processes of differentiation and reproduction.
- tumor suppressor genes. These protein particles usually protect a person from cancer. Suppressors at the right time stop cell growth and control tissue repair. Damage to the structure of suppressor genes causes uncontrolled cell growth, which is a trigger for tumor formation.
- DNA repair genes. These elements take part in the process of detection and neutralization of individual mutations in the DNA cell. If the repair gene is damaged, the number of gene mutations increases.
Cancer cells under a microscope:
Where do cancer cells come from?
The development of a malignant neoplasm is preceded by a latent period, when the total number of gene mutations accumulates in the body. In this period, the probability of tumor formation is directly proportional to the age of the patient.
- Initiation. Numerous Scientific research indicate that a key role in the occurrence of cancer belongs to gene mutations. In some cases, the formation of a cancer cell is preceded by translocation (part of the chromosome moves to another part of the DNA cell). Also, the occurrence of oncology is affected by a violation of intracellular regenerative processes.
- Promotion. The formation of a malignant neoplasm is influenced by the number of mutations and the presence of provoking factors. For the formation of a cancerous tumor, a combination of chromosomal pathology and exposure to carcinogens is necessary.
- Progression. Oncological transformation of a cell makes it function and develop in a completely different way. occurs due to the double number of division of cancer cells. The number of doublings depends on the type of cancer and the degree of aggressiveness of tumor growth.
Cancer cell - photo:
Metastasis
tend to spread beyond the primary focus. In such cases, destruction of nearby tissues and the formation of secondary tumors occur. The transfer of mutated cells is carried out through the lymphoid and circulatory systems. Cancer metastasis is considered the main cause of death in cancer patients.
